Steam-engine controller.



No. 680,!72. Patented Aug. 6, IQOI..

v R. J. PATTERSON.

STEAM ENGINE CDNTROLLER.

(Application filed Oct. 4, 1900.)

MWW-

UNITED STATES PATENT OFFICE.

RALrH J. PATTERSON, or WOBURN, MASSACHUSETTS.

sTEAM-ENGNE CONTROLLE'R.

SPECIFICATION forming part of Letters Patent No. 680,172, dated August 6, 1901.

Application filed October 4, 1900. Serial No 31.953. (No model.) i

the speed of the engine will influence the cut-off for the cylinder, so that the engine will be more sensitive and will respond more' quickly to changes in load than engines as ordinarily built.

In most engines now in use the speed of the engine is controlled by some form of cen'trifugal governor which is directly connected to the valve-gear, such governor Operating as the speed ofthe engine varies through the said connections to vary the cut-off for the cylinder, so that when the engine increases its speed the cut-off will be shortened and when the speed of the engine slackens the cut-off will be correspondingly lengthened to admit more stean to the cylinder. One ob- 'jection to engines constructed as above is that the centrifugal governor mustbe heavy enough to operate the parts connecting the same with the cut-off. It is obvious that a heavy governor will not respond as quickly to any changes in load as a lighter governorv and will not therefore control the speed of the engine as accurately as such lighter governor would; but heretofore it has been impossible to use an extremely light and sensitive governor, because such a governor would not be heavy enough to operate the connections between it and the cut-off.

In my present invention I overcome the above-noted objections by providing a suitable pressure-chamber and utilizing the variations in pressure in said chamber to control the cut-off for the cylinder, the variations in pressure in the said chamber being controlled by the speed of the engine. One

convenient Way of accomplishing this is to control a Valve leading to the said pressurechamber by means of a suitable centrifugal governor which is operated by the engine in the usual way, and such ball-governor can be made very light and will be correspondingly sensitive, so that variations in the pressure in said pressure-chanber will occur exactly as the speed of the engine varies, such variations in pressure Operating mechanism which in turn Controls the cut-off.

One embodinent of my invention is illustrated in the drawings forninga part of this application, in which- Figure 1 is a. view showing one form of mechanism. Fig. 2 is a view showing a slightly-modified construction. Fig. -3 is an enlarged detail showing one form of valve, and Fig. 4: is a detail showing the slotted link on an enlarged scale;

My inventio may be applied to various types of engines; but as illustrating one convenient application thereof I have shown diagranmaticallyin the drawings part of an engine of the Corliss type, C representing the cylinder and 21 representin g the inlet-valves, the eXhaust-valves being represented by e. Herein the cylinderand val ves are illustrated diagrammatically only, for as they are of any familiar Corliss type it is not deemed necessary to show the oscillating disk and connections by which the valves are opened and closed, they forming no part of my present invention. The inlet-valves v are controlled as to the time of their cut-off by the rods 4', which are connected to opposite ends of a fulcrum-lever Z, as is usual in this class of device, the said lever Z, as illustrated in Fig. 1, being connected to the slotted link 3 by means of the connection c and the link being pivotally mounted upon any suitable stationary point, it being illustrated in the drawings as mounted at 4: upon the standard which supports the governor `g; but I wish it understood that this particular arrangement is not essential.

Instead of connecting the link 3 directly with the governor g, as in nost engines of this' class, I provide mechanism whereby the said link is operated by variations in pressure in a suitable pressure-chamber, such -variations in turn being caused by mechanism controlled 'by the speed of the engine.

IOO

The pressure-chamber p may be of any suitform shown-4'. e., what is known as a pistenpot, wherein the casing is made in two parts bolted together and having clamped between them a suitable diaphragm, one side of which is connected to the Operating mechanisn which controls the link 3 and the other side of which is subjected to the pressure in the pipe 13, which in this instance is steam-pres` sure. The steam-pressurein 'the pressurechamber is controlled by a suitable valve device (represented generally by 14) which is situated in an exhaust-pipe'l, connected to the pressure-chamber and leading to some point of much lower pressure than the pressure iu pipe 13, which may be connected to any suitable source of pressure-supply and conmunicaes with the pressure-chamber. If the pipe 13 is connected to the boiler, then the pipe 15 Would preferably connect with the rcceiver if the controller were used in con nection With a multiple-cylinder engine or with the atmosphere if used to control a single-cylinder engine, and if the pipe 13 should be In this enbodiment of my invention the` operation ot' the valve 14 is made automatic by Operating the same by any suitable een'- trifugal governor, whereby as the speed of the engine increases the valve is opened wider and the pressure in the pressure-chamber.

` correspondingly decreased, such decrease i-n pressu'e Operating to shortenthe cut-off, and as the engine slackens its speed the valve is correspondingly closed to therebyincrease the pressure in the chamber, and hence lengthen the cut-off.

g represents the governor, which may be of any type,that shown being the familiar bal1- governor, it being of usual Construction, except that itis comparativelysmall and is therefore more sensitive than a heavier governor would be. The said governor has the usual arm 17 projecting therefrom, which is connected by means of rod 18 to the lever 19, which in turn is connected to the valve-stern 20, the said lever preferably being pivotally mounted on an arm 21 on the valve-casing.

Any suitable valve 14 may be used; but I have found that good results fiow from the use of a double-ported throttle-Valve, such as is illustrated in Fig. 3-, in which 22 is the inlet and 23 the outlet, the valve-body 24 being fitted to and seating on the two seats 25 and 26 when the valve is closed. One advantage of this type of valve is that it is a balanced 'valve and can therefore be operated by a comparatively small force.

As illustrated in the drawings, the exhaustpipe 15 is much larger than the inlet-pipe 13,

thus allowing the steam to freely exhaust when the valve is opened or partially opened.

As herein illustrated, the diaphragn in the pressure-chamberp has connected thereto at one side the plunger or piston-rod 5, pivotally connected to the lever 6, said lcver being pivotally mounted in any suitable way, preferably upon an arm 7 upon the diaphragm-casing, and carrying at one end th'e weights w. A second lever S is pivotally nounted upon a suitable stand 9, the said lever carrying at one end a roll 10, which plays in the cam-slot 11 in the link 3, as shown in the drawings, the opposite end of the lever 8 being connected by anysuitable mechanism with' the lever 6. The pipe 13, communicatiug with the source ot steam-supply, which may be either the boiler or receiver, leads into the pressure-chamber 19, as stated above, whereby the diaphragm is constantly subject to the steam-pressure.

With this Construction of device the operation will be as follows: As the speed of the engine increases the balls of the ball-governor will fly outwar'd and will thereby raise the arn 17 in a well-known manner, the arm through the connection described Operating to open the valve, and thereby reduce the pressure in the pressure-chamber p; The weight's w, which are attached to the end of the arm ot the lever G, will operate as the pressure in the pressure-chanber is reduced to Swing said lever about its fulcrun 'and through the rod 16 wil'l swing the right-hand end of lever 8 downward, thereby swinging the link 3 to the right and through the reachrod r shortening the cut-off to the cylinder. As the speed of the engine falls the reverse action will take pla'ce-that is, the valve 24 willbe partially closed and ,the pressure in the pressure chamber correspondingly increased, such increased pressure Operating to depress the piston-rod 5, and thereby raise the right-hand end of the lever 8, and hence lengthen the cut-ofi.

From the above description it will be seen that the governor in my engine has only to control the valve 24, and hence can be made extremely light, for as the type of valve which I prefer to use in my device is a balanced valve, such as shown, it will be evident that a Very slight force is required to manipulate the same.

The reach-rod and connecting parte of the cut-off, which require consider-able force to operate, are positively operated by variations of pressure in the pressure-chamber.

In Fig. 2 I have illustrated a slightly-modified form of apparatus, and in this Construction the Valve-stem -20 is connected directly to the governor g instead of being connected through the arms 17 and the lever 19, as in Fig. 1. In other respects the device of Fig.

2 is essentially the same as that in Fig. 1, the lever 6, however, being connected to the bellcrank 31, which in turn is connected to the reach--od to the valVe-geart p If desh-able, I may -substitute for the bellcrank 31, Fig. 2, a lcver similar to lever S,

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Fig. 1, which in turn operates the slotted link to control the cut-off.

Any suitable safety-Valve 35 is employed in the pipe 13, so that should excessive pres sure arise in the source of supply the safety- Valve would relieve such pressure, and thereby prevent damage to the diaphragm.

As illustrated in Fig. 1, the slot in the link 3 is a double cam-slot, the purpose of this construction being to provide mechanism whereby should the belt b, for instance, break the mechanisn herein illustrated would operate as a stop device to stop the engine and prevent damage.

The Construction of the link is such that when the roll 10 is at either extremity of the slot the inlet-valves of the cylinder are closed, and when the roll 10 is central in the slot the cut-ofi is lengthened to its maximum extent.

As stated above, as the speed of the engine increases the right-hand end of the lever 8 is swung downwa-d to thereby shorten the cutoif, and should the engine develop abnormal speed the operation will continue until the roll 10 is at the lower extremity of the slot, in which case the inlet-Valves will be closed. If, on the other hand, the belt b, which drives the governor, should break, the goVernor-arms will immediately fall and close the Valve 24. The maximum pressure would then be exerted on the diaphragm in the pressure-chamber, and the lever 8 would be turned until the roll 10 was at the upper eXtremit-y of the slot, in which case the inlet-valves would be closed again, and thereby stop the engine. I may also apply my-invention to any steam-engine as a stop device, such device when used in this capacity being auxiliary to the ordinary means for controlling the speed of the engine.

Then used as a stop device, I prefer to use the form of mechanism illustrated in Fig. 2, except that the Valve-stem 20 would be connected to the governor by means of a flexible connection, such as the chain shown in dotted lines in saidfigure, and in this use of the apparatus the governor g would be connected up to the Cilli-Off, so as to 'normally operate it in the ordinary way, and would also be connected to the valve-stem 20 by a fieXible means. With such a Construction under normal conditions the governor g will control the speed of the engine in the ordinary way; but when abnormal or danger speed is developed for any reason the governor-arms will fly out suhciently so as to take up the slack in the chain and raise the valve-stem 20, to thereby open the valve and reduce the pressure in the pressure-chamber p, such reduction of pressure Operating to shorten the cut-off to a minimum, in which case the engine will take no steam and of course stop. V

It will be obvious that various changes can be made in the Construction of the device without departing from ny invention, which comprises a mechanism for controlling a steamengine in which variations of steam-pressure in a pressure chamber operate mechanism which in turn controls the cut-aft" for the engine, such variations in pressure being controlled by the variations in the speed of the engine, and I would consider as coming within my invention any device which embodies the above features.

I have herein illustrated my device in connection with a single-cylinder engine; but I wish it understood that it may be applied equally as well to any multiple-cylinder engine.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In an engine-controller, a pressure-chamber, means connecting the same with the source of steam-supply for the engine, means governed by the speed of the engine to control the steam-pressurein said pressure-chamber, and means operated by variations in the steam-pressu re in the said chamber to control the cut-off.

2. In an engine-controller, a cut-off for the cylinder, a pressure-chamber, means connecting the same with the source of steam-supply for the cylinder, a ball-governor, means op-- erated by said ball-governor to control the steam-pressure in the steam-chamber, and means operated by variations in the pressure in said chamber to control said cut-off.

3. In an engine-controller, a pressure-chamber, a pipe connecting said chamber with the source of steam-supply for the engine, a movable member in said pressure-chamber operated by variations of steam-pressure therein, connections between said movable member and the cut-off, and means operated by the,

speed of the engine to control the steam-pressure in said pressure-chamber.

4. In an engine-controller, a cut-off for the cylinder, a pressure-chamber, a pipe connecting said chanber with the source of steam-suppl y for the cylinder,a diaphragm in said chamber, means connecting the diaphragm with the cut-off, whereby variations in steam-pressure in said chamber vary the cut-off, and means' governed by the speed of the engine to control the pressure in said chamber.

5. In an engine-controller, a cut-off for the cylinder, a pressure-chamber, a pipe connecting said chamber with the source of steam-supply for the cylinder,a diaphragm in said chamber, means connecting the diaphragm with the cut-off whereby variations in steam-pressure in said chamber vary the cut-oli, a centrifugal governor governed by the speed of the engine and means operated by said governor to control the pressure in said pressurechamber.

6. In an engine-controller,a pressure-chamber, means for connecting the same with the source of steam-supply for the engine, a ValVe controlling the exhaust therefrom,means controlled by the speed of the engine for operating said valve, movable means in said chamber operated by.variation in the steam-pressure therein, and mechanism connecting said IOO IIO

movable means with the cnt-off of the engine, whereby the pressure in said chamber varies with the speed of the engine, and such variation operates to control the cut-off.

'7. In an engine-contr01ler,a pressure-charnber, a pivoted link having a cam-slot, a reachrod to the cut-off operated by said link, a Iever engaging said cam-slot, means operated by Variations in the pressure in said chamber to operate said lever, and means controlled by the speed of the engine to vary the pressure in said pressure-chamber.

8. In an engine-controller, a pivoted link having a. double cam-slot, a reach-red connected to said link and controlling the cut-off, a pivoted lever having one end engaging the slot and controlling the position of the link, L pressu re-c11arnber,mechanisn controlled by the speed of the engine for varying the pressnre in said chamber, and 'means operated by the Variations in the pressure in said chamber and connected to said lever, whereby such variations in pressure control the cnt-Ott, the construction being such that whenever the lever is at either extreme of the slot, the inlet-valvesare closed.

9. In an engine-controller, a cut-off for th &30,172

cylindege piston-pot having a diaphragnr therein, a pipe connecting said pisten-pot i With the source of steam-supply for the en- 30 gine, a Valve controlling the exhaust from e said piston-pot,neans controlled by the speed of the engine for Operating said Valve, a plune ger connected to the diaphragm, a lever connected with the plunger, and connections be- 3 5 tween the lever and cut-o& whereby variations in the pressure of the steam in the piston-pot control the cut-off. e

, 10. In an engine-eontroller, a cut-oli for the cylinder, a pressure-chamber connected With a source of stearn-supply, said chamber having an ontlet, a valve in said outlet, a centrifngal governor connected thei-eto whereby the speed. of the engine Controls the pressure in the pressure-chamber, and means operated 45 by variations of -the pressure in said pressurechanber to control said cut-of& V

In testinony whereof I have signed my name to this specification in the presence of two snbscribing witnesses.

` RALPH J. PATTERSON. Witnesses:

JOHN O. EDWARDS, LOUIS C. SMITH. 

